Crucible-furnace.



G. E. BEHRENS.

GBUGIBLE FURNACE.

APPLICATION FILED MAY 11, 1911 1,01 3,472. I Patented Jan.2, 1912.

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GEORGE E. BEHRENS, 0F IVOBYTON,

CONNECTICUT, ASSIGNOR T0 JOSE]? VEIT, OF NEW YORK, N. Y.

CRUCIBLE-FURNACE.

Application filed May 11, 1911.

To all whom it may concern:

Be it known that I, GEORGE E. BEI-IRENS, a citizen of the United States, residing at Ivoryton, in the county of Middlesex and State of Connecticut, have invented certain new and useful Improvements in Crucible- Furnaces, of which the following is a speclfication.

This furnace is especially designed for melting metals in a crucible, being constructed to circulate a reducing or non-0x1- dizing gas over the surface of the metal in the crucible.

The preferred furnace is illustrated in the accompanying drawing, in which the figure is a transverse vertical section, in the plane of the draft-pipe.

The furnace illustrated comprises a cylindrical metal casing 1, the heating chamber of which has a lining 2 of firebrick. A grate 3 serves as a support for the crucible 4 and for the bed of fuel, surrounding the lower part of the crucible. A draft-door 5 opens into the ashpit beneath the grate. The casing 1 is closed at its upper end by a removable top-plate 6. A draft-pipe 7, containing a revoluble damper 8, extends horizontally and then vertically from an opening 9 in the casing 1 above its lining 2. The top 6 has a central opening 10, over which is secured a vertical flue-piece 11, closed at its upper end by a removable cap 12 containing a-peep-hole 13. A cross-pipe 14, containing a revoluble damper 15, connects the fluepiece 11 and the draft-pipe 7. A vertical tube 16 extends downward through the opening 10 and into the upper end of the crucible, being removably seated on a shoulder 17 at the lower end of the flue-piece 11. A pipe 18 for supplying hydrogen or other gas opens into the heating chamber. The crucible 4, in large furnaces, may be stationary and provided with an outlet 19 for the molten metal.

In operation, the crucible is charged with the metal to be melted and fuel is placed on the grate around it. The top 6 and pipe 16 are put in place, the door 5 and damper 8 are opened, and the damper 15 is closed. The fuel is ignited and as soon as it is in active combustion the damper 8 is closed and Specification of Letters Patent.

Patented Jan. 2,1912.

Serial No. 626,522.

the damper 15 is opened, whereupon the burning gases rising from the fuel pass inward over the edge of the crucible, thence downward over the metal therein, and finally upward through the passages 16, 11 and 14 into the draft-pipe 7, as indicated by the arrows. The metal is thus heated both indirectly by the heat conducted through the crucible and directly by the burning gases passing downward over its surface, and is soon melted. The gases entering the crucible, being of a reducing character and containing a considerable percentage of carbon monoxid, exclude air from the metal and effect reduction of any oxid rising to its surface. I-Iydrogen or other gases may be supplied to the furnace-chamber through the pipe 18, if desired. The operation may be watched through the peep-hole 13, and the molten metal may be stirred by removing the cover 12 and inserting a rod through the passages 11 and 16. The molten metal may be tapped out through the opening 19, or if the furnace and crucible are small, the top 6, with its pipes 16, 11 and 14, may be lifted OH and the crucible then removed by tongs and tilted to discharge its contents.

I claim:

1. A furnace for melting metals, compris ing a casing, a fuel-grate, a crucible, a draftinlet beneath said grate, a draft-pipe connected to the furnace-chamber above said grate, and a tube depending into said crucible and connected to said draft-pipe.

2. A furnace for melting metals, comprising a casing, a fuel-grate, a crucible, a draftinlet beneath said grate, a draft-pipe connected to the furnace-chamber above said grate, a tube depending into said crucible, a cross connection between said tube and draft-pipe, and dampers in said cross-connection and draft-pipe.

3. A furnace for melting metals, compris- 4. A furnace for melting metals, 'comprissaid cross-connection and draft-pipe, and a ing a casing having a removable apertured gas-inlet t0 the furnace-chamber. 10 top, a fuel-grate, a crucible, a draft-inlet be- In testimony whereof, I afiiX my signature neath said grate, a draft-pipe connected to in presence of two Witnesses.

the furnace-chamber above said grate, a re- GEORGE E. BEHRENS. movable tube extending through said top Witnesses:

and into said crucible, a cross-connection be- LOUIS SOHAFRAN,

tween said tube and draft-pipe, dampers in J. FALCON.

Gopiesof this patent may be obtained for five cents each, by addressing the Commissioner 01 Patents,

Washington, I). C. 

